MCP Server
Mappstack maps software systems as C4 diagrams from system context down to code, plus data models, OpenAPI 3.2 specs, event contracts, job schedules, state machines and business capability maps. Claude reads and writes the same map you edit in the web editor, and every save is validated against its notation's rules.
Connect
- In Claude, open Connectors in Settings and add Mappstack. To add it by URL instead, use
https://app.mappstack.com/mcp. - Sign in with your Mappstack account email and open the sign-in link we send you.
You need a Mappstack account.
Tools
| Tool | Does | Access |
|---|---|---|
audit_project | Whole project in one call: elements, L1 to L4 tree, gaps, TBD decisions, invalid diagrams | Read |
overview | Every project and its diagrams by notation | Read |
list_projects | Every project | Read |
list_diagrams | Diagrams in a project for one notation | Read |
get_diagram | A diagram's document and etag | Read |
list_elements | Every element in a project | Read |
list_notations | Available notations | Read |
get_notation_schema | A notation's rules, template, palette and examples | Read |
create_project | New project | Write |
create_diagram | New diagram, declaring any new elements it draws | Write |
create_element | New element no diagram draws, such as a state field | Write |
rename_project | Change a project title | Write, asks first |
set_project_stage | Move a project between design and build | Write, asks first |
rename_diagram | Change a diagram title | Write, asks first |
update_element | Change an element everywhere it is drawn | Write, asks first |
write_diagram | Replace a diagram's whole document | Write, asks first |
delete_diagram | Remove a diagram, keeping its elements | Delete, asks first |
delete_element | Remove an element and every reference to it | Delete, asks first |
Notations
c4 system context to code, erd data models, api OpenAPI 3.2 specs, events event contracts, schedule jobs, state state machines, bcm business capability maps.
Example prompts
- Audit my Payments project and list every open TBD decision.
- Draw the L2 container diagram for the Auth Platform system.
- Add a data model for the Orders database with orders, line items and customers.
- Rename the Billing Service element to Invoicing Service everywhere.
Limits
120 MCP requests per minute per IP address. Request bodies up to 1 MB.